Conductive polyphenylene ether-polyamide blend

ABSTRACT

The present invention relates to a thermoplastic resin composition and a method for making the same. The composition comprises the reaction product of about 10 wt % to about 50 wt % polyphenylene ether, about 35 wt % to about 65 wt % polyamide, preferably about 0.4 wt % to about 3.0 wt % carbon fibrils, and optionally about 5 wt % to about 40 wt % talc, up to about 10 wt % compatibilizing agent and up to about 20 wt % impact modifier. The method comprises forming a carbon masterbatch with polyamide and introducing the masterbatch and the polyamide subsequent to compounding the polyphenylene ether with a compatibilizing agent.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation application of U.S. patentapplication Ser. No. 09/438,998 filed Nov. 12, 1999, the contents ofwhich is hereby incorporated by reference in its entirety.

BACKGROUND OF INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a conductive thermoplasticresin, and especially relates to a conductive polyphenyleneether-polyamide blend.

[0004] 2. Brief Description of the Related Art

[0005] Poly(phenylene ether) resins (referred to hereafter as “PPE”) arecommercially attractive materials because of their unique combination ofphysical, chemical, and electrical properties. Furthermore, thecombination of these resins with polyamide (PA) resins intocompatibilized blends results in additional overall properties such aschemical resistance, high strength, and high flow. Examples of suchcompatibilized blends can be found in U.S. Pat. Nos. 4,315,086 (Ueno, etal); 4,659,760 (van der Meer); and 4,732,938 (Grant, et al). Theproperties of these blends can be further enhanced by the addition ofvarious additives such as impact modifiers, flame retardants, lightstabilizers, processing stabilizers, heat stabilizers, antioxidants andfillers.

[0006] The physical properties of PPE/polyamide blends make themattractive for a variety of end-use articles, for example, in theautomotive market, for various exterior components. Dimensional behaviorof these components is critical due to the differences in coefficient ofthermal expansion, which can be improved by adding fillers(organic/inorganic) as known to those skilled in the art.

[0007] U.S. Pat. No. 5,591,382 to Nahass et al., discloses a polymericcomposition comprising carbon fibrils, at least a portion of which arein the form of aggregates, wherein, as measured on an area basis,substantially all of the aggregates are less than about 35μ in diameter.The polymeric composition is prepared by combining the carbon fibrilswith a polymeric material, mixing the combination to distribute thefibrils in the polymeric material and applying shear to the combinationto break down the aggregates until substantially all of the aggregatesare less than about 35μ in diameter. Nahass et al. teach the use of alower loading of the conductive fibrils in order to achieve a certainconductivity while retaining better impact performance compared tocarbon black or carbon fibers.

[0008] Although numerous PPE/polyamide compositions having a variety ofproperties are available, compositions having alternative properties arecontinuously sought in the industry.

SUMMARY OF INVENTION

[0009] The present invention relates to a thermoplastic resincomposition and a method for making the same. The composition comprises:about 10 weight percent (wt %) to about 50 wt % polyphenylene ether,about 35 wt % to about 65 wt % polyamide, about 5 wt % to about 40 wt %talc, and about 0.4 wt % to about 3.0 wt% carbon.

[0010] The method comprises: forming a talc masterbatch comprising about40 wt% to about 50 wt % talc and about 50 wt % to about 60 wt %polyamide; forming a carbon masterbatch comprising about 10 wt % toabout 30 wt % carbon and about 70 wt % to about 90 wt % polyamide;introducing polyphenylene ether and a compatibilizer to an extruder;maintaining the extruder at a sufficient temperature to melt thepolyphenylene ether; introducing polyamide, said carbon masterbatch tothe extruder at a downstream port; forming a thermoplastic compositioncomprising the reaction product of about 10 weight percent (wt %) toabout 50 wt % polyphenylene ether; about 35 wt % to about 65 wt %polyamide; and about 0.4 wt % to about 3.0 wt % carbon.

BRIEF DESCRIPTION OF DRAWINGS

[0011] Referring now to the drawings which are meant to be illustrative,not limiting:

[0012]FIG. 1 is a graph of melt volume rate (MVR) as a function ofspecific volume resistivity (SVR).

[0013]FIG. 2 is a graph of melt viscosity (MV) as a function of specificvolume resistivity (SVR).

DETAILED DESCRIPTION

[0014] The thermoplastic composition of the present invention comprisesboth the mixture and reaction product(s) of: polyphenylene ether,polyamide, talc, and carbon fibrils, along with, optionally,compatibilizers, impact modifiers and various additives. Thethermoplastic composition can comprise about 10 weight percent (wt %) toabout 50 wt % polyphenylene ether, about 35 wt % to about 65 wt %polyamide, about 5 wt % to about 40 wt % talc, and about 0.4 wt % toabout 3.0 wt %A carbon (preferably in the form of fibrils), with about15 wt % to about 30 wt % polyphenylene ether, about 45 wt % to about 55wt % polyamide, about 15 wt % to about 25 wt % talc, about 0.6 wt % toabout 1.5 wt % carbon fibrils, and optionally from 0 to about 10 wt %compatibilizer and from 0 to about 20 wt % impact modifier, preferred,(balance additives) based on the total weight of the composition.

[0015] Poly(arylene) ether

[0016] Although all conventional poly(arylene ether)s can be employedwith the present invention, polyphenylene ethers (“PPE”) are preferred.polyphenylene ethers are known polymers comprising a plurality ofstructural units of the formula (I):

[0017] wherein for each structural unit, each Q¹ is independentlyhalogen, primary or secondary lower alkyl (e.g., alkyl containing up to7 carbon atoms), phenyl, haloalkyl, aminoalkyl, hydrocarbonoxy, orhalohydrocarbonoxy wherein at least two carbon atoms separate thehalogen and oxygen atoms; and each Q² is independently hydrogen,halogen, primary or secondary lower alkyl, phenyl, haloalkyl,hydrocarbonoxy or halohydrocarbonoxy as defined for Q¹. Preferably, eachQ¹ is alkyl or phenyl, especially C₁₋₄ alkyl, and each Q² is hydrogen.

[0018] Both homopolymer and copolymer poly(arylene ether) are included.The preferred homopolymers are those containing 2,6-dimethylphenyleneether units. Suitable copolymers include random copolymers containing,for example, such units in combination with2,3,6-trimethyl-1,4-phenylene ether units or copolymers derived fromcopolymerization of 2,6-dimethylphenol with 2,3,6-trimethylphenol. Alsoincluded are poly(arylene ether) containing moieties prepared bygrafting vinyl monomers or polymers such as polystyrenes, as well ascoupled poly(arylene ether) in which coupling agents such as lowmolecular weight polycarbonates, quinones, heterocycles and formalsundergo reaction in known manner with the hydroxy groups of twopoly(arylene ether) chains to produce a higher molecular weight polymer.Poly (arylene ether)s of the present invention further includecombinations of any of the above.

[0019] The polyphenylene ether generally has a number average molecularweight within the range of about 3,000-40,000 and a weight averagemolecular weight within the range of about 20,000-80,000, as determinedby gel permeation chromatography. The poly(arylene ether) generally hasan intrinsic viscosity often between about 0.10-0.60 deciliters per gram(dl/g), preferably in the range of about 0.29-0.48 dl/g, all as measuredin chloroform at 25° C. It is also possible to utilize a high intrinsicviscosity poly(arylene ether) and a low intrinsic viscosity poly(aryleneether) in combination. Determining an exact ratio, when two intrinsicviscosities are used, will depend somewhat on the exact intrinsicviscosities of the poly(arylene ether) used and the ultimate physicalproperties that are desired.

[0020] The polyphenylene ether are typically prepared by the oxidativecoupling of at least one monohydroxyaromatic compound such as2,6-xylenol or 2,3,6-trimethylphenol. Catalyst systems are generallyemployed for such coupling; they typically contain at least one heavymetal compound such as a copper, manganese or cobalt compound, usuallyin combination with various other materials.

[0021] Particularly useful polyphenylene ether for many purposes arethose which comprise molecules having at least one aminoalkyl-containingend group. The aminoalkyl radical is typically located in an orthoposition to the hydroxy group. Products containing such end groups maybe obtained by incorporating an appropriate primary or secondarymonoamine such as di-n-butylamine or dimethylamine as one of theconstituents of the oxidative coupling reaction mixture. Also frequentlypresent are 4-hydroxybiphenyl end groups, typically obtained fromreaction mixtures in which a by-product diphenoquinone is present,especially in a copper-halide-secondary or tertiary amine system. Asubstantial proportion of the polymer molecules, typically constitutingas much as about 90% by weight of the polymer, may contain at least oneof said aminoalkyl-containing and 4-hydroxybiphenyl end groups.

[0022] It will be apparent to those skilled in the art from theforegoing that the polyphenylene ether contemplated for use in thepresent invention include all those presently known, irrespective ofvariations in structural units or ancillary chemical features.

[0023] Polyamide

[0024] The polyamide resins useful in the practice of the presentinvention are a generic family of resins known as nylons, characterizedby the presence of an amide group (—C(O)NH—). Nylon-6 and nylon-6,6 arethe generally preferred polyamide5 and are available from a variety ofcommercial sources. Other polyamides, however, such as nylon-4,6,nylon-12, nylon-6,10, nylon 6,9, nylon 6/6T and nylon 6,6/6T withtriamine contents below about 0.5 weight percent, as well as others,such as the amorphous nylons may be useful for particular polyphenyleneether-polyamide applications. Mixtures of various polyamides, as well asvarious polyamide copolymers, are also useful. The most preferredpolyamide for the blends of the present invention is polyamide-6,6.

[0025] The polyamides can be obtained by a number of well knownprocesses such as those described in U.S. Pat. Nos. 2,071,250;2,071,251; 2,130,523; 2,130,948;

[0026]2,241,322; 2,312,966; and 2,512,606. Nylon-6, for example, is apolymerization product of caprolactam. Nylon-6,6 is a condensationproduct of adipic acid and 1,6-diaminohexane. Likewise, nylon 4,6 is acondensation product between adipic acid and 1,4-diaminobutane. Besidesadipic acid, other useful diacids for the preparation of nylons includeazelaic acid, sebacic acid, dodecane diacid, as well as terephthalic andisophthalic acids, and the like. Other useful diamines include m-xylyenediamine, di-(4-aminophenyl)methane, di-(4-aminocyclohexyl)methane;2,2-di-(4-aminophenyl)propane, 2,2-di-(4-aminocyclohexyl)propane, amongothers. Copolymers of caprolactam with diacids and diamines are alsouseful.

[0027] Polyamides having viscosity of up to about 400 ml/g can be used,with a viscosity of about 90 to about 350 ml/g preferred, and about 110to about 240 ml/g especially preferred, as measured in a 0.5 wt %solution in 96 wt % sulphuric acid in accordance with ISO 307.

[0028] Fillers

[0029] Preferably a sufficient amount of filler is employed to reducethe coefficient of thermal expansion, improve dimensional behavior (flowas well as cross flow) of the composition without having too much of anegative effect on surface finish, flow and impact. Although mica, talc,clay, glass fibers, and other fillers can be employed, talc ispreferably employed as at least one of the filler(s) due to bettersurface finish and reduced effect on impact strength compared to glassfibers (for example), and greater reduction in the coefficient ofthermal expansion compared to clays (for example). Although from 0 toabout 50 wt % filler can be used, based on the total weight of thethermoplastic composition, about 5 to about 40% filler is preferred,with about 1 S wt % to about 25 wt % especially preferred. The talc ispreferably a Mg-silicate with an average particle size of about 3.0microns to about 5.0 microns, with an average size of about 4.0 micronsto about 5.0 microns preferred; with particle size distribution ofgreater than about 90% under about 20 microns, with greater than about95% under about 20 microns preferred, and about 98% or greater under 20microns especially preferred.

[0030] Conductive Material

[0031] The conductive material can be any material which does notsignificantly adversely effect the physical characteristics of thethermoplastic composition, such as carbon and the like. The carbon canbe in the form of carbon black (“CCB”; e.g. Ketjenblack EC 600 JDavailable from AKZO, Deventer, The Netherlands), and carbon fibrils(“CF”), (e.g., BN fibrils available from Hyperion CatalysisInternational, Cambridge, Mass. 01921 USA), with carbon fibrilspreferred, such as those disclosed in patent WO/94/23433. Carbon fibrilsare typically in the form of vermicular tubes with graphitic outerlayers disposed substantially concentrically about the cylindrical axisof the fibril. Preferably, the fibrils are substantially free of apyrolytically deposited thermal carbon overcoat. Carbon fibrils have alength-to-diameter ratio of at least 5, and more preferably at least100. Even more preferred are fibrils whose length-to-diameter ratio isat least 1,000. The wall thickness of the fibrils is about 0.1 to 0.4times the fibril external diameter, which is preferably between 3.5 and75 nanometers.

[0032] Compatibilizing Agent

[0033] In blends of the present invention, a compatibilizing agentshould be employed in the preparation of the composition in amounts upto about 25 wt %, with 0 to about 10 wt % preferred, and about 0.4 toabout 3.0 wt % especially preferred, based on the total weight of thecomposition. The two-fold purpose for using compatibilizing agents is toimprove, in general, the physical properties of the polyphenyleneether-polyamide resin blend, as well as to enable the use of a greaterproportion of the polyamide component. When used herein, the expression“compatibilizing agent” refers to those polyfunctional compounds whichinteract with either the polyphenylene ether, the polyamide resin, orboth. This interaction may be chemical (e.g. grafting) or physical (e.g.affecting the surface characteristics of the dispersed phases). Ineither instance the resulting polyphenylene ether-polyamide compositionappears to exhibit improved compatibility, particularly as evidenced byenhanced impact strength, mold knit line strength and/or elongation. Asused herein, the expression “compatibilized polyphenyleneether-polyamide base resin” refers to those compositions which have beenphysically or chemically compatibilized with an agent as discussedabove, as well as those compositions which are physically compatiblewithout such agents, as taught in U.S. Pat. No. 3,379,792.

[0034] Examples of the various compatibilizing agents that may beemployed in the practice of the present invention include: a) liquiddiene polymers, b) epoxy compounds, c) oxidized polyolefin wax, d)quinones, e) organosilane compounds, f) polyfunctional compounds andfunctionalized polyphenylene ether as described obtained by reacting oneor more of the previously mentioned compatibilizing agents withpolyphenylene ether hereinafter.

[0035] Liquid diene polymers (a) suitable for use herein includehomopolymers of a conjugated diene with at least one monomer selectedfrom other conjugated dienes;

[0036] vinyl monomer, e.g. styrene and alphamethyl styrene; olefins,e.g. ethylene, propylene, butene-1, isobutylene, hexene-1, octene-1 anddodecene-1, and mixtures, thereof, having a number average molecularweight of about 150 to about 10,000 preferably about 150 to about 5,000.These homopolymers and copolymers can be produced by the methodsdescribed in, for example, U.S. Pat. Nos. 4,054,612; 3,876,721 and3,428,699 and include, among others, polybutadiene, polyisoprene, poly(1,3-pentadiene), poly(butadiene-isoprene), poly(styrene-butadiene),polychloroprene, poly(butadiene-alpha methylstyrene),poly(butadiene-styrene-isoprene), poly(butylene-butadiene), and thelike.

[0037] Epoxy compounds (b) suitable for use in the practice of thepresent invention include: (1) epoxy resins produced by condensingpolyhydric phenols (e.g. bisphenol-A, tetrabromobisphenol-A, resorcinoland hydroquinone) and epichlorohydrin; (2) epoxy resins produced bycondensing polyhydric alcohols (e.g., ethylene glycol, propylene glycol,butylene glycol, polyethylene glycol, polypropylene glycol,pentaerythritol and trimethylolethane and the like) and epichlorohydrin,(3) glycidyletherified products of monohydric alcohols and monohydricphenols including phenyl glycidylether, butyl glycidyl ether and cresylglycidylether; (4) glycidyl derivates of amino compounds for example,the diglycidyl derivate of aniline, (5) epoxidized products of higherolefinic or cycloalkene, or natural unsaturated oils (e.g. soybean) aswell as of the foregoing liquid diene polymers; and the like.

[0038] Oxidized polyolefin waxes (c) are well known and an illustrativedescription thereof and processes for the production of the same arefound in U.S. Pat. Nos. 3,822,227 and 3,756,999. Generally, these areprepared by an oxidation or suspension oxidation of polyolefin. Anespecially preferred polyolefin wax is “Hoechst Wachs”.

[0039] Quinone compounds (d) suitable for use herein are characterizedas having in the molecule of the unsubstituted derivative at least onesix-membered carbon ring; at least two carbonyl groups in the ringstructure, both of which may be in the same or, if more than one ring,different rings, provided that they occupy positions corresponding tothe 1,2- or 1,4-orientation of the monocyclic quinone; and at least twocarbon-carbon double bonds in the ring structure, said carbon-carbondouble bounds and carbonyl carbon-oxygen double bonds in the ringstructure, said carbon-carbon double bonds and carbonyl carbon-oxygendouble bonds being conjugated with respect to each other. Where morethan one ring is present in the unsubstituted quinone, the rings may befused, non-fused, or both: non-fused rings may be bound by a directcarbon-carbon double bond or by a hydrocarbon radical having conjugatedunsaturation such as —C═C—C═C—.

[0040] Substituted quinones are also within the scope of the presentinvention. The degree of substitution; where substitution is desired,may be from one to the maximum number of replaceable hydrogen atoms.Exemplary of the various substituents that may be present on theunsubstituted quinone structures include halogen (e.g. chlorine,bromine, fluorine, etc.), hydrocarbon radicals including branched andunbranched, saturated and unsaturated alkyl, aryl, alkyl aryl andcycloalkyl radicals and halogenated derivatives thereof; and similarhydrocarbons having hetero atoms therein, particularly oxygen, sulfur,or phosphorous and wherein the same connects the radical to the quinonering (e.g. oxygen link).

[0041] Exemplary of the various quinones there may be given 1,2- and1,4-benzoquinone; 2,6-diphenyl quinone; tetramethyldiquinone; 2,2′- and4,4′-diphenoquinone; 1,2-, 1,4- and 2,6-naphthoquinone; chloranils;2-chloro-1,4-benzoquinone; 2,6-dimethyl benzoquinone; and the like.

[0042] Organosilane compounds (e) suitable as compatibilizing agents arecharacterized as having in the molecule (a) at least one silicon atombonded to a carbon through an oxygen link and (b) at least onecarbon-carbon double bond or carbon-carbon triple bond and/or afunctional group selected from an amine group or a mercapto groupprovided that the functional group is not directly bonded to the siliconatom.

[0043] In such compounds, the C—O—Si component is generally present asan alkoxyl or acetoxy group bonded directly to the silicon atom, whereinthe alkoxy or acetoxy group generally has less than 15 carbon atoms andmay also contain hetero atoms (e.g. oxygen). Additionally, there mayalso be more than one silicon atom in the compound, such multiplesilicon atoms, if present, being linked through an oxygen link (e.g.siloxanes), a silicon bond; or a bifunctional organic radical (e.g.methylene or phenylene groups); or the like.

[0044] Examples of suitable organosilane compounds include: gamma aminopropyltriethoxy silane, 2-(3-cyclohexanyl)ethyl trimethoxy silane; 1,3-divinyl tetraethoxy silane; vinyl tris-(2-methoxyethoxy)silane;5-bicycloheptenyl triethoxy silane and gamma mercapto propyl trimethoxysilane.

[0045] Polyfunctional compounds (f) which may be employed ascompatibilizer in the practice of the present invention are of threetypes. The first type of polyfunctional compounds are those having inthe molecule both (a) a carbon-carbon double bond or a carbon-carbontriple bond and b) at least one carboxylic acid, anhydride, amide,ester, imide, amino, epoxy, orthoester, or hydroxy group. Examples ofsuch polyfunctional compounds include maleic acid; maleic anhydride;fumaric acid; glycidyl acrylate, itaconic acid; aconitic acid;maleimide; maleic hydrazide; reaction products resulting from a diamineand maleic anhydride, maleic acid, fumaric acid, etc.; dichloro maleicanhydride; maleic acid amide; unsaturated dicarboxylic acids (e.g.acrylic acid, butenoic acid, methacrylic acid, t-ethylacrylic acid,pentenoic acid); decenoic acids, undecenoic acids, dodecenoic acids,linoleic acid, etc.); esters, acid amides or anhydrides of the foregoingunsaturated carboxylic acids; unsaturated alcohols (e.g. alkyl alcohol,crotyl alcohol, methyl vinyl carbinol, 4-pentene-1-ol,1,4-hexadiene-3-ol, 3-butene-1,4-diol, 2,5-dimethyl-3-hexene-2,5-dioland alcohols of the formula C_(n)H_(2n-5)OH, C_(n)H_(2n-7)OH andC_(n)H_(2n-9)OH, wherein n is a positive integer up to 30); unsaturatedamines resulting from replacing from replacing the —OH group(s) of theabove unsaturated alcohols with NH₂ groups; and functionalized dienepolymers and copolymers; and the like. Of these, two of the preferredcompatibilizing agents for compositions of the present invention aremaleic anhydride and fumaric acid.

[0046] The second group of polyfunctional compatibilizer compoundssuitable for use herein are characterized as having both (a) a grouprepresented by the formula (OR) wherein R is hydrogen or an alkyl, aryl,acyl or carbonyl dioxy group and (b) at least two groups each of whichmay be the same or different selected from carboxylic acid, acid halide,anhydride, acid halide anhydride, ester, orthoester, amide, imido,amino, and various salts thereof. Typical of this group ofcompatibilizers are the aliphatic polycarboxylic acids, acid esters andacid amides represented by the formula:

[0047] (RIO)mR(COORIT)n(CONRIIIRV)s

[0048] wherein R is a linear or branched chain, saturated aliphatichydrocarbon of from 2 to 20, preferably 2 to 10, carbon atoms; R^(I) ishydrogen or an alkyl, aryl, acyl or carbonyl dioxy group of 1 to 10,preferably 1 to 6, most preferably 1 to, 4, carbon atoms, especiallypreferred is hydrogen; each R^(II) is independently hydrogen or an alkylor aryl group from 1 to 20 carbon atoms, preferably from 1 to 10 carbonatoms; each R^(III) and R^(IV) are independently hydrogen or an alkyl oraryl group of from 1 to 10, preferably from 1 to 6, most preferably 1 to4, carbon atoms; m is equal to 1 and (n+s) is greater than or equal to2, preferably equal to 2 or 3, and n and s are each greater than orequal to zero and wherein (OR^(I)) is alpha or beta to a carbonyl groupand at least two carbonyl groups are separated by 2 to 6 carbon atoms.Obviously, R^(I), R^(II), R^(III) and R^(IV) cannot be aryl when therespective substituent has less than 6 carbon atoms.

[0049] Suitable polycarboxylic acids include, for example, citric acid,malic acid, agaricic acid, and the like; including the variouscommercial forms thereof, such as for example, the anhydrous andhydrated acids. Of these, citric acid is another of the preferredcompatibilizing agents. Illustrative of esters useful herein include,for example, acetyl citrate and mono- and/or distearyl citrates and thelike. Suitable amides useful herein include, for example, N,N′-diethylcitric acid amide; N-phenyl citric acid amide; N dodecyl citric acidamide; N,N′-didodecyl citric acid amide and N-dodecyl malic acid presentinvention. Especially preferred derivates are the salts thereof,including the salts with amines and/preferably, the alkali and alkalinemetal salts. Exemplary of suitable salts include calcium malate, calciumcitrate, potassium malate, and potassium citrate.

[0050] The third group of polyfunctional compatibilizer compoundssuitable for use herein are characterized as having in the molecule both-(a) an acid halide group, most preferably an acid chloride group and(b) at least one carboxylic acid, anhydride, ester, epoxy, orthoester,or amide group, preferably a carboxylic acid or anhydride group.Examples of compatibilizers within this group include trimelliticanhydride acid chloride, chloroformyl succinic anhydride, chloro formylsuccinic acid, chloroformyl glutaric anhydride, chloroformyl glutaricacid, chloroacetyl succinic anhydride, chloroacetylsuccinic acid,trimellitic acid chloride, and chloroacetyl glutaric acid. Among these,trimellitic anhydride acid chloride is preferred. Furthermore, it isespecially preferred that compatibilizers of this group be prereactedwith at least a portion of the polyphenylene ether whereby thecompatibilizing agent is a polyphenylene ether-functionalized compound.

[0051] The foregoing compatibilizing agents are more fully described inU.S. Pat. Nos. 4,315,086; 4,600,741; 4,642,358; 4,826,933; 4,927,894;4,980,424; 5,041,504; and 5,115,042.

[0052] The foregoing compatibilizing agents may be used alone or invarious combinations of one another with another. Furthermore, they maybe added directly to the melt blend or pre-reacted with either or boththe polyphenylene ether and polyamide, as well as with other resinousmaterials employed in the preparation of the compositions of the presentinvention. With many of the foregoing compatibilizing agents,particularly the polyfunctional compounds, even greater improvement incompatibility is found where at least a portion of the compatibilizingagent is pre-reacted, either in the melt or in a solution of a suitablesolvent, with all or a part of the polyphenylene ether. It is believedthat such pre-reacting may cause the compatibilizing agent to react withthe polymer and, consequently, functionalize the polyphenylene ether asnoted above. For example, the polyphenylene ether may be pre-reactedwith maleic anhydride to form an anhydride functionalized polyphenyleneether which has improved compatibility with the polyamide compared to anon-functionalized polyphenylene ether.

[0053] Where the compatibilizing agent is employed in the preparation ofthe compositions of the present invention, the initial amount used willbe dependent upon the specific compatibilizing agent chosen and thespecific polymeric system to which is added.

[0054] It is possible to use in the composition according to theinvention any other known compatibilization system. Other systems havebeen described for example in U.S. Pat. No. 4,866,114.

[0055] Impact Modifiers

[0056] All impact modifiers as generally used for compositionscomprising a polyphenylene ether, a polyamide or a combination of apolyphenylene ether and a polyamide can be used, typically in an amountup to about 50%, with amounts of from 0 to about 20% preferred based onthe total weight of the composition. Particularly suitable are the socalled block copolymers, for example, A-B-A triblock copolymers and A-Bdiblock copolymers. The A-B and A-B-A type block copolymer rubberadditives which may be used are thermoplastic rubbers comprised of oneor two alkenyl aromatic blocks which are typically styrene blocks and arubber block, e.g., a butadiene block which may be partiallyhydrogenated. Mixtures of these triblock copolymers and diblockcopolymers are especially useful.

[0057] Suitable A-B and A-B-A type block copolymers are disclosed in,for example, U.S. Pat. Nos. 3,078,254, 3,402,159, 3,297,793, 3,265,765,and 3,594,452 and U.K. Patent 1,264,741. Examples of typical species ofA-B and A-B-A block copolymers include polystyrene-polybutadiene (SBR),polystyrene poly(ethylene-propylene), polystyrene-polyisoprene,poly(α-methylstyrene)-polybutadiene,polystyrene-polybutadiene-polystyrene (SBR),polystyrene-poly(ethylene-propylene)-polystyrene,polystyrene-polyisoprene-polystyrene andpoly(α-methylstyrene)-polybutadiene-poly(α-methylstyrene), as well asthe selectively hydrogenated versions thereof, and the like. Mixtures ofthe aforementioned block copolymers are also useful. Such A-B and A-B-Ablock copolymers are available commercially from a number of sources,including Phillips Petroleum under the trademark SOLPRENE, ShellChemical Co., under the trademark KRATON, Dexco under the tradenameVECTOR, and Kuraray under the trademark SEPTON.

[0058] A useful amount of impact modifier is up to about 20 weightpercent (wt %), with about 1 wt % to about 15 wt % preferred, and about2 wt % to about 10 wt % especially preferred, wherein the weightpercentages are based on the entire weight of the composition.

[0059] Additives

[0060] Compositions of the present invention can also include effectiveamounts of at least one additive selected from anti-oxidants, flameretardants, drip retardants, dyes, pigments, colorants, stabilizers,antistatic agents, plasticizers, lubricants, and mixtures thereof. Theseadditives are known in the art, as are their effective levels andmethods of incorporation. Effective amounts of the additives varywidely, but they are usually present in an amount up to about 50 wt % ormore, based on the weight of the entire composition. Especiallypreferred additives include hindered phenols, thio compounds and amidesderived from various fatty acids. The preferred amounts of theseadditives generally ranges up to about 2 wt % total combined weightbased on the total weight of the composition.

[0061] Preparation

[0062] The preparation of the thermoplastic compositions can normally beachieved by merely blending the ingredients under conditions for theformation of an intimate blend. Such conditions often include mixing insingle or twin screw type extruders or similar mixing devices which canapply a shear to the components.

[0063] All of the ingredients may be added initially to the processingsystem, or else certain additives may be precompounded with one or moreof the primary components, preferably the polyphenylene ether, impactmodifier and the polyamide.

[0064] A masterbatch of talc can be made with polyamide, at a ratio ofabout 5 wt % to 50 wt % talc, balance polyamide possible, with a ratioof about 40% to about 50% talc, balance polyamide preferred. Similarly,fibrils are also preferably part of a masterbatch with polyamide. Thefibril ratio can be about 10% to about 30% fibrils, with about 15% toabout 25% fibrils, balance polyamide preferred. The level of filler in amasterbatch is usually limited by a number of factors like, wettingbehavior of filler by carrier polymer, viscosity increase of carrierpolymer due to filler loading, etc.

[0065] For example, the thermoplastic composition can be made bycompounding polyphenylene ether and a compatibilizer in an extruder,while maintaining the extruder at a sufficient temperature to melt thepolyphenylene ether. The polyamide, a carbon masterbatch, and optionallythe talc (or a filler) masterbatch can then be introduced to theextruder at a downstream port. The compounded mixture, polyamide, carbonmasterbatch and talc masterbatch are then mixed to form thethermoplastic composition. The composition can be formed into pellets,sheets, film, coating, various components, or the like.

[0066] Alternatively, the polyphenylene ether, compatibilizer and talccan be added to the extruder with a portion of the polyamide (e.g. up toabout 10 wt % of the polyamide). These components can then be compoundedprior to introducing the remainder of the polyamide and acarbon/polyamide masterbatch. Again, the compounded mixture, polyamide,and carbon masterbatch can then be mixed to form the thermoplasticcomposition.

[0067] It appears that certain properties, such as impact strength andelongation, are sometimes enhanced by initially precompounding thepolyphenylene ether and impact modifier, optionally with any otheringredients, prior to compounding with the polyamide resin, however,these improvements are done at the expense of increasing the viscosityof the compatibilized composition. It is preferable that at least about5 wt %, preferably at least about 8 wt %, and most preferably at leastabout 10 wt % polyamide be added with the polyphenylene ether andnon-polymeric carboxylic acid. The remaining portion of the polyamide isfed through a port downstream. In this manner, the viscosity of thecompatibilized composition is reduced without significant reduction inother key physical properties.

[0068] While separate extruders may be used in the processing, thesecompositions are preferably prepared by using a single extruder havingmultiple feed ports along its length to accommodate the addition of thevarious components. It is often advantageous to apply a vacuum oratmospheric pressure to the melt through at least one or more vent portsin the extruder to remove volatile impurities in the composition. Thoseof ordinary skill in the art will be able to adjust blending times andtemperatures, as well as component addition, without undue additionalexperimentation.

[0069] It should be clear that the reaction products, compositions andarticles made from the compositions made by the method of thisdisclosure are within the scope of the invention.

[0070] All patents cited are incorporated herein by reference.

[0071] The invention will be further described by the following exampleswhich are meant to be illustrative, not limiting.

EXAMPLES

[0072] Thermoplastic compositions A through I comprising thecompositions set forth in the Table were prepared as follows:

[0073] Pre-mixes of 45 wt % talc Finntalc Ml 5 from SA Omya Benelux NV,Brussels, Belgium and 55 wt % low IV polyamide (masterbatch talc/low IVPA) (i.e. with a viscosity, according ISO 307, between 123-129 ml/g);and 20 wt % carbon fibrils (BN fibrils as produced by Hyperion CatalysisInternational, Cambridge, Mass. 02138, USA) and 80 wt % low IV polyamide(masterbatch carbon/low IV PA) were prepared.

[0074] [t1] TABLE Formulation (Units: parts) A B C D E F G H I PPE 22.822.8 22.8 22.8 22.8 22.8 22.8 22.8 22.8 low IV PA 49.9 49.9 49.9 49.949.9 49.9 49.9 49.9 49.9 SEBS**** 6 6 6 6 6 6 6 6 6 Additives* 1.81 1.811.81 1.81 1.81 1.81 1.81 1.81 1.81 TALC** 19.3 19.3 19.3 19.3 19.3 19.319.3 19.3 19.3 CCB 1.4 1.6 1.8 2.0 2.2 CF*** 1.0 1.2 1.4 1.6 PropertiesSpecific Volume 26.15 0.616 0.239 0.153 15.92 2.88 2.34 0.8 0.47Resistivity (kOhm · cm) Melt Volume 22.2 18.2 16.1 14.2 17.7 13.5 12.99.4 8.1 Rate (cm³/10 min.) Melt Viscosity 145 142 144 150 185 192 190198 188 (Pa · s) Unnotched Izod 39 35 38 34 38 37 39 33 27 Impact(kJ/m²)

[0075] Materials have been produced on a Werner & Pfleiderer 28 extruderwere, for formulations A-D polyphenylene ether, compatibilizer, impactmodifier, flow promoter and stabilizers were fed via the first part ofthe extruder and the masterbatches (talc/PA & fibrils/PA) as well as PAwere fed in a down stream feedport located on approximately ⅓ of theextruder. For formulations E-l same procedure was done, except for theCCB which was fed in a down stream feedport located on approximately ⅔of the extruder. Temperature settings of the machine:260-300-305-305-305-290-295-305-305-300-310° C. Melt temperatureapproximately 335° C., throughout rate 12 kg/hr, screw speed 300 rpm.

[0076] The properties were determined using ISO 1133 for melt volumerate (MVR) at (280° C./50 Newtons (N)); ISO 11443, 282° C./1,500seconds⁻¹ (s) for melt viscosity (MV); and ISO 180 for unnotched Izodimpact.

[0077] The specific volume resistivity was determined using a Netstal 60molding machine having a screw diameter of 32 millimeters (mm), using a285° C. (±5° C.) processing temperature, a mold temperature of 100° C.(±5° C.), a mass injection press I of 1,600 (±100) bar, a mass injectionpress II of 1,350 (±100) bar, an injection speed of 3.0 (±5) centimetersper second (cm/s), a cooling time of 25 (±2) seconds, and a total cycletime of 41 (±5) seconds. The tensile bar (ISO 3167) was notched with arazor blade on both ends of the narrow parallel portion. After the twoadjacent sections were then broken in a brittle fashion, both fracturesurfaces were painted with silver paint which was allowed to dry for atleast 0.5 hours. The resistance was measured using a multimeter, and,using the dimensions of the part, the specific volume resistivity (SPV)was determined according to:

[0078] SPV=(resistance measured)(width)(height/length).

[0079] As can be seen from Blends A-D versus E-I, a substantialreduction in melt viscosity was achieved employing the carbon fibrilsand the talc. Blends A-D attained a significantly lower melt viscosity,about 150 Pa•s or less, while Blends E-I possessed melt viscositiesexceeding 180 Pa•s.

[0080] Surprisingly it was discovered that for the same conductivityrange a composition made using a carbon fibril masterbatch did show asignificant improvement in flow performance over a conductive carbonblack composition without showing any significant difference in impactperformance. Consequently, since the thermoplastic composition of thepresent invention advantageously effects flow, it can be employed toproduce thinner parts (i.e. in thinner applications) and/or producelarger parts having a thickness comparable to conventional parts havinga polyphenylene ether/polyamide composition. This invention isparticularly useful in producing electrostatically paintable components,such as automotive parts and the like.

1. A thermoplastic resin composition, comprising: about 10 wt % to about50 wt % polyphenylene ether; about 35 wt % to about 65 wt % polyamide;about 5 wt % to about 40 wt % talc; and about 0.4 wt % to about 3.0 wt %carbon fibrils; wherein the polyphenylene ether as an intrinsicviscosity of about 0.10 dl/g to about 0.60 dl/g as measured inchloroform at 25° C.
 2. A thermoplastic resin composition as in claim 1,further comprising about 1 wt % to about 15 wt % impact modifier.
 3. Athermoplastic resin composition as in claim 1, wherein the polyphenyleneether comprises two polyphenylene ether components having differentintrinsic viscosities.
 4. A thermoplastic resin composition as in claim1, further comprising about 1 wt % to about 15 wt % impact modifier. 5.A thermoplastic resin composition as in claim 1, wherein the intrinsicviscosity is about 0.29 dl/g to about 0.48 dl/g.
 6. A thermoplasticresin composition as in claim 1, wherein the polyamide has a viscosityof about 90 ml/g to about 350 ml/g as measured in a 0.5 wt % solution in96 wt % sulphuric acid in accordance with ISO
 307. 7. A thermoplasticresin composition as in claim 6, wherein the viscosity is about 110 ml/gto about 240 ml/g.
 8. A thermoplastic resin composition as in claim 8,further comprising at least one additive, wherein said additives areanti-oxidants, flame retardants, drip retardants, dyes, pigments,colorants, stabilizers, antistatic agents, plasticizers, lubricants, ormixtures thereof; and at least one filler wherein said filler is mica,glass fibers, clay or mixtures thereof.
 9. A thermoplastic resin as inclaim 1, comprising about 1.0 wt % to about 1.6 wt % carbon fibrils. 10.A thermoplastic resin as in claim 9, comprising about 1.2 wt % to about1.6 wt % carbon fibrils.
 11. A thermoplastic resin composition,comprising: about 10 wt % to about 50 wt % polyphenylene ether; about 35wt % to about 65 wt % polyamide; about 5 wt % to about 40 wt % talc;about 0.4 wt % to about 3.0 wt % carbon fibrils; and about 1 wt % toabout 1I5 wt % impact modifier; wherein the polyphenylene ether as anintrinsic viscosity of about 0.10 dl/g to about 0.60 dl/g as measured inchloroform at 25° C.
 12. A thermoplastic resin composition as in claim11, comprising about 2 wt % to about 10 wt % of the impact modifier. 13.A thermoplastic resin composition, comprising the reaction product of:about 10 wt % to about 50 wt % polyphenylene ether; about 35 wt % toabout 55 wt % polyamide; about 5 wt % to about 40 wt % talc; from 0 toabout 10 wt % compatibilizing agent; and about 0.4 wt % to about 3.0 wt% carbon fibrils; wherein the polyphenylene ether as an intrinsicviscosity of about 0.10 dl/g to about 0.60 dl/g as measured inchloroform at 25° C.
 14. A thermoplastic resin composition as in claim13, wherein the polyphenylene ether comprises two polyphenylene ethercomponents having different intrinsic viscosities.
 15. A thermoplasticresin composition as in claim 13, further comprising about 1 wt % toabout 15 wt % impact modifier.
 16. A thermoplastic resin composition asin claim 13, wherein the intrinsic viscosity is about 0.29 dl/g to about0.48 dl/g.
 17. A thermoplastic resin composition as in claim 13, whereinthe polyamide has a viscosity of about 90 ml/g to about 350 ml/g asmeasured in a 0.5 wt % solution in 96 wt % sulphuric acid in accordancewith ISO
 307. 18. A thermoplastic resin composition as in claim 17,wherein the viscosity is about 110 ml/g to about 240 ml/g.
 19. Athermoplastic resin composition as in claim 18, further comprising atleast one additive, wherein said additives are anti-oxidants, flameretardants, drip retardants, dyes, pigments, colorants, stabilizers,antistatic agents, plasticizers, lubricants, or mixtures thereof; and atleast one filler wherein said filler is mica, glass fibers, clay ormixtures thereof.